Move simple DrawString into examples

The "real" version of DrawString is the only one we need to make generally available. The single-uint32 glyphs are more of a toy example that we can keep relegated to the example code.
npiegdon · Jan 15, 2022 · 8b4988d · 8b4988d
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diff --git a/drawing.cpp b/drawing.cpp
@@ -259,10 +259,6 @@ void SaveImage(unsigned int suffix)
 //
 void Present(const std::vector<Color> &screen);
 
-// This is the same DrawString from the Text example, available here so other examples (or you)
-// can use it without a lot of distracting copy-paste.
-void DrawString(int x, int y, const std::string &s, const Color c, bool centered = false);
-
 // Lets you draw using the raw GDI+ Graphics object if that's something you're interested in
 void Draw(std::function<void(Gdiplus::Graphics &g)> f);
 
@@ -503,36 +499,6 @@ void DrawRectangle(int x, int y, int width, int height, Color fill, Color stroke
     SetDirty();
 }
 
-
-// For a line-by-line breakdown of this single-function text rendering library, see the Text example.  (This version has
-// been compacted a bit and made a little more generic so we can draw directly into the density field in the smoke example.)
-void DrawString(int x, int y, const string &s, const Color c, bool centered, function<void(int x, int y, Color c)> customDraw)
-{
-    static constexpr uint32_t Font[128 - 32] = {
-        0x10000000, 0x10000017, 0x30000C03, 0x50AFABEA, 0x509AFEB2, 0x30004C99, 0x400A26AA, 0x10000003, 0x2000022E, 0x200001D1, 0x30001445, 0x300011C4, 0x10000018, 0x30001084, 0x10000010, 0x30000C98,
-        0x30003A2E, 0x300043F2, 0x30004AB9, 0x30006EB1, 0x30007C87, 0x300026B7, 0x300076BF, 0x30007C21, 0x30006EBB, 0x30007EB7, 0x1000000A, 0x1000001A, 0x30004544, 0x4005294A, 0x30001151, 0x30000AA1,
-        0x506ADE2E, 0x300078BE, 0x30002ABF, 0x3000462E, 0x30003A3F, 0x300046BF, 0x300004BF, 0x3000662E, 0x30007C9F, 0x1000001F, 0x30003E08, 0x30006C9F, 0x3000421F, 0x51F1105F, 0x51F4105F, 0x4007462E,
-        0x300008BF, 0x400F662E, 0x300068BF, 0x300026B2, 0x300007E1, 0x30007E1F, 0x30003E0F, 0x50F8320F, 0x30006C9B, 0x30000F83, 0x30004EB9, 0x2000023F, 0x30006083, 0x200003F1, 0x30000822, 0x30004210,
-        0x20000041, 0x300078BE, 0x30002ABF, 0x3000462E, 0x30003A3F, 0x300046BF, 0x300004BF, 0x3000662E, 0x30007C9F, 0x1000001F, 0x30003E08, 0x30006C9F, 0x3000421F, 0x51F1105F, 0x51F4105F, 0x4007462E,
-        0x300008BF, 0x400F662E, 0x300068BF, 0x300026B2, 0x300007E1, 0x30007E1F, 0x30003E0F, 0x50F8320F, 0x30006C9B, 0x30000F83, 0x30004EB9, 0x30004764, 0x1000001F, 0x30001371, 0x50441044, 0x00000000,
-    };
-
-    if (centered) x -= accumulate(s.begin(), s.end(), 0, [](int a, char b) { return a + (b < 32 ? 0 : (Font[b - 32] >> 28) + 1); }) / 2;
-    for (auto i : s)
-    {
-        if (i < 32 || i > 127) continue;
-        uint32_t glyph = Font[i - 32];
-        const int width = glyph >> 28;
-        for (int u = x; u < x + width; ++u) for (int v = y; v < y + 5; ++v, glyph = glyph >> 1) if ((glyph & 1) == 1) customDraw(u, v, c);
-        if (width > 0) x += width + 1;
-    }
-}
-
-void DrawString(int x, int y, const string &s, const Color c, bool centered)
-{
-    DrawString(x, y, s, c, centered, DrawPixel);
-}
-
 void DrawString(int x, int y, const char *text, const char *fontName, int fontPtSize, const Color c, bool centered)
 {
     if (!text || !fontName) return;

diff --git a/example7_nibbles.cpp b/example7_nibbles.cpp
@@ -1,4 +1,5 @@
 #include "drawing.h"
+#include <numeric>
 #include <string>
 #include <deque>
 using namespace std;
@@ -30,9 +31,6 @@ struct Snake
 Snake snakes[2];
 
 
-// Secret functions from drawing.cpp!
-void DrawString(int x, int y, const string &s, const Color c, bool centered = false);
-
 // We draw the play field at double-size to reach the 80x50 size of the original
 void SetBigPixel(int x, int y, Color c)
 {
@@ -50,6 +48,36 @@ Color GetBigPixel(int x, int y)
     return ReadPixel(x * 2, y * 2 + 10);
 }
 
+// For a line-by-line breakdown of this single-function text rendering library,
+// see the Text example.  (This version has been compacted and is a bit terse.)
+void DrawString(int x, int y, const string &s, Color c, bool centered = false)
+{
+    static constexpr uint32_t Font[128 - 32] = {
+        0x10000000, 0x10000017, 0x30000C03, 0x50AFABEA, 0x509AFEB2, 0x30004C99, 0x400A26AA, 0x10000003, 0x2000022E, 0x200001D1, 0x30001445, 0x300011C4, 0x10000018, 0x30001084, 0x10000010, 0x30000C98,
+        0x30003A2E, 0x300043F2, 0x30004AB9, 0x30006EB1, 0x30007C87, 0x300026B7, 0x300076BF, 0x30007C21, 0x30006EBB, 0x30007EB7, 0x1000000A, 0x1000001A, 0x30004544, 0x4005294A, 0x30001151, 0x30000AA1,
+        0x506ADE2E, 0x300078BE, 0x30002ABF, 0x3000462E, 0x30003A3F, 0x300046BF, 0x300004BF, 0x3000662E, 0x30007C9F, 0x1000001F, 0x30003E08, 0x30006C9F, 0x3000421F, 0x51F1105F, 0x51F4105F, 0x4007462E,
+        0x300008BF, 0x400F662E, 0x300068BF, 0x300026B2, 0x300007E1, 0x30007E1F, 0x30003E0F, 0x50F8320F, 0x30006C9B, 0x30000F83, 0x30004EB9, 0x2000023F, 0x30006083, 0x200003F1, 0x30000822, 0x30004210,
+        0x20000041, 0x300078BE, 0x30002ABF, 0x3000462E, 0x30003A3F, 0x300046BF, 0x300004BF, 0x3000662E, 0x30007C9F, 0x1000001F, 0x30003E08, 0x30006C9F, 0x3000421F, 0x51F1105F, 0x51F4105F, 0x4007462E,
+        0x300008BF, 0x400F662E, 0x300068BF, 0x300026B2, 0x300007E1, 0x30007E1F, 0x30003E0F, 0x50F8320F, 0x30006C9B, 0x30000F83, 0x30004EB9, 0x30004764, 0x1000001F, 0x30001371, 0x50441044, 0x00000000,
+    };
+
+    if (centered) x -= accumulate(s.begin(), s.end(), 0, [](int a, char b) { return a + (b < 32 ? 0 : (Font[b - 32] >> 28) + 1); }) / 2;
+
+    for (auto i : s)
+    {
+        if (i < 32 || i > 127) continue;
+        uint32_t glyph = Font[i - 32];
+        const int width = glyph >> 28;
+        for (int u = x; u < x + width; ++u)
+            for (int v = y; v < y + 5; ++v, glyph = glyph >> 1)
+                if ((glyph & 1) == 1)
+                    DrawPixel(u, v, c);
+
+        if (width > 0) x += width + 1;
+    }
+}
+
+
 const Color Walls = LightRed;
 const Color Background = Blue;
 const Color Text = White;

diff --git a/example8_smoke.cpp b/example8_smoke.cpp
@@ -1,7 +1,6 @@
 #include "drawing.h"
 
 #include <vector>
-#include <functional>
 #include <algorithm>
 using namespace std;
 
@@ -162,9 +161,8 @@ void velocityStep(vector<float> &u, vector<float> &v, vector<float> &u0, vector<
 
 
 
-// Secret functions from drawing.cpp!
+// We use a secret function from drawing.cpp that lets us update every pixel at once
 void Present(const vector<Color> &screen);
-void DrawString(int x, int y, const string &s, const Color c, bool centered, function<void(int x, int y, Color c)> customDraw);
 
 // Generate a color based on our preferred visualization
 Color FluidColor(float u, float v, float density, bool showVelocity)
@@ -210,7 +208,36 @@ void MouseDrag(vector<float> &field, int x1, int y1, int x2, int y2, float value
     // velocity and density vector fields with single points, it makes the interaction more fun if
     // we scratch out an entire line segment between the previous and current mouse coordinates
     const auto points = Line(x1, y1, x2, y2);
-    for (auto p : points) field[id(p.first, p.second)] = value / points.size();
+    for (const auto &p : points) field[id(p.first, p.second)] = value / points.size();
+}
+
+// For a line-by-line breakdown of this single-function text rendering library,
+// see the Text example.  (This version has been compacted a bit and made a
+// little more generic so we can draw directly into the density field in this smoke example.)
+void DrawString(vector<float> &density, int y, const char *s)
+{
+    static constexpr uint32_t Font[128 - 32] = {
+        0x10000000, 0x10000017, 0x30000C03, 0x50AFABEA, 0x509AFEB2, 0x30004C99, 0x400A26AA, 0x10000003, 0x2000022E, 0x200001D1, 0x30001445, 0x300011C4, 0x10000018, 0x30001084, 0x10000010, 0x30000C98,
+        0x30003A2E, 0x300043F2, 0x30004AB9, 0x30006EB1, 0x30007C87, 0x300026B7, 0x300076BF, 0x30007C21, 0x30006EBB, 0x30007EB7, 0x1000000A, 0x1000001A, 0x30004544, 0x4005294A, 0x30001151, 0x30000AA1,
+        0x506ADE2E, 0x300078BE, 0x30002ABF, 0x3000462E, 0x30003A3F, 0x300046BF, 0x300004BF, 0x3000662E, 0x30007C9F, 0x1000001F, 0x30003E08, 0x30006C9F, 0x3000421F, 0x51F1105F, 0x51F4105F, 0x4007462E,
+        0x300008BF, 0x400F662E, 0x300068BF, 0x300026B2, 0x300007E1, 0x30007E1F, 0x30003E0F, 0x50F8320F, 0x30006C9B, 0x30000F83, 0x30004EB9, 0x2000023F, 0x30006083, 0x200003F1, 0x30000822, 0x30004210,
+        0x20000041, 0x300078BE, 0x30002ABF, 0x3000462E, 0x30003A3F, 0x300046BF, 0x300004BF, 0x3000662E, 0x30007C9F, 0x1000001F, 0x30003E08, 0x30006C9F, 0x3000421F, 0x51F1105F, 0x51F4105F, 0x4007462E,
+        0x300008BF, 0x400F662E, 0x300068BF, 0x300026B2, 0x300007E1, 0x30007E1F, 0x30003E0F, 0x50F8320F, 0x30006C9B, 0x30000F83, 0x30004EB9, 0x30004764, 0x1000001F, 0x30001371, 0x50441044, 0x00000000,
+    };
+
+    // Center the line
+    int textWidth = 0;
+    for (const char *i = s; *i; ++i) textWidth += (*i < 32 ? 0 : (Font[*i - 32] >> 28) + 1);
+    int x = (Width - textWidth) / 2;
+
+    for (const char *i = s; *i; ++i)
+    {
+        if (*i < 32 || *i > 127) continue;
+        uint32_t glyph = Font[*i - 32];
+        const int width = glyph >> 28;
+        for (int u = x; u < x + width; ++u) for (int v = y; v < y + 5; ++v, glyph = glyph >> 1) if ((glyph & 1) == 1) density[id(u, v)] = 3.0f;
+        if (width > 0) x += width + 1;
+    }
 }
 
 void run()
@@ -221,12 +248,11 @@ void run()
     vector<float> u(Size), v(Size), uPrev(Size), vPrev(Size), density(Size), densityPrev(Size);
     vector<Color> screen(Width * Height);
 
-    auto drawToSmoke = [&density](int x, int y, Color c) { density[id(x, y)] = 3.0f; };
-    DrawString(Width / 2, 1 * Height / 7, "Left mouse drag to move air",          0, true, drawToSmoke);
-    DrawString(Width / 2, 2 * Height / 7, "Right mouse drag to add smoke",        0, true, drawToSmoke);
-    DrawString(Width / 2, 3 * Height / 7, "Holding both is the most fun!",        0, true, drawToSmoke);
-    DrawString(Width / 2, 5 * Height / 7, "Use spacebar to toggle velocity view", 0, true, drawToSmoke);
-    DrawString(Width / 2, 6 * Height / 7, "(Press 'C' to clear the screen)",      0, true, drawToSmoke);
+    DrawString(density, 1 * Height / 7, "Left mouse drag to move air");
+    DrawString(density, 2 * Height / 7, "Right mouse drag to add smoke");
+    DrawString(density, 3 * Height / 7, "Holding both is the most fun!");
+    DrawString(density, 5 * Height / 7, "Use spacebar to toggle velocity view");
+    DrawString(density, 6 * Height / 7, "(Press 'C' to clear the screen)");
 
     bool showVelocity = false;
     bool mouseWasDown = false;