UI core boiler plate

game/ui_widgets.c

@@ -0,0 +1,152 @@
+#include "ui.h"
+
+UIGrid uiGridFromRoot(i32 width, i32 height) {
+    return (UIGrid) {.bounds = {0, 0, width, height}};
+}
+UIGrid uiGridFromGrid(const UIGrid grid, i32 row, i32 col) {
+    return uiGridFromGridSpan(grid, row, col, 1, 1);
+}
+UIGrid uiGridFromGridSpan(const UIGrid grid, i32 row, i32 col, i32 rowSpan, i32 colSpan) {
+    Rectangle bounds = uiGridCellSpan(grid, row, col, rowSpan, colSpan);
+    return (UIGrid) {
+        .rowPadding = grid.rowPadding,
+        .cellPadding = grid.cellPadding,
+        .bounds = bounds
+    };
+}
+
+Rectangle uiGridCell(const UIGrid grid, i32 row, i32 col) {
+    return uiGridCellSpan(grid, row, col, 1, 1);
+}
+Rectangle uiGridCellSpan(const UIGrid grid, i32 row, i32 col, i32 rowSpan, i32 colSpan) {
+    BZ_ASSERT(grid.rows > 0 && grid.cols > 0);
+    BZ_ASSERT(rowSpan > 0 && colSpan > 0);
+    BZ_ASSERT(row >= 0 && col >= 0);
+    BZ_ASSERT(row + rowSpan <= grid.rows);
+    BZ_ASSERT(col + colSpan <= grid.cols);
+
+    f32 cellWidth = (grid.bounds.width - (grid.cols - 1) * grid.cellPadding) / grid.cols;
+    f32 cellHeight = (grid.bounds.height - (grid.rows - 1) * grid.rowPadding) / grid.rows;
+
+    Rectangle cellBounds = {
+            .width  = cellWidth * colSpan,
+            .height = cellHeight * rowSpan,
+            .x      = (cellWidth + grid.cellPadding) * col,
+            .y      = (cellHeight + grid.rowPadding) * row,
+    };
+    return cellBounds;
+}
+
+void uiGridDrawCells(const UIGrid grid) {
+    BZ_ASSERT(grid.rows > 0 && grid.cols > 0);
+    DrawRectangleLines(grid.bounds.x, grid.bounds.y, grid.bounds.width, grid.bounds.height, RED);
+
+    for (i32 rowIdx = 0; rowIdx < grid.rows; rowIdx++) {
+        for (i32 colIdx = 0; colIdx < grid.cols; colIdx++) {
+            Rectangle rec = uiGridCell(grid, rowIdx, colIdx);
+            DrawRectangleLines(rec.x, rec.y, rec.width, rec.height, BLUE);
+        }
+    }
+
+}
+
+static f32 getX(const Rectangle rec) {
+    return rec.x;
+}
+static f32 getY(const Rectangle rec) {
+    return rec.y;
+}
+static f32 getWidth(const Rectangle rec) {
+    return rec.width;
+}
+static f32 getHeight(const Rectangle rec) {
+    return rec.height;
+}
+
+typedef f32 (*FlexBoxGetFunc)(const Rectangle rec);
+
+void uiFlexBoxCalc(const FlexBoxDesc *desc, i32 numElements, ...) {
+    if (numElements <= 0) return;
+    f32 totalWidth = 0;
+    f32 totalHeight = 0;
+
+    UIFlexBoxFlag flags = desc->flags;
+
+    // Calculate total size of elements in the main axis
+    va_list ap;
+    va_start(ap, numElements);
+    for (i32 i = 0; i < numElements; i++) {
+        const Rectangle *rec = va_arg(ap, Rectangle *);
+        totalWidth += rec->width;
+        totalHeight += rec->height;
+    }
+    va_end(ap);
+
+    // Default: DIR_ROW
+    FlexBoxGetFunc axisX = getX, axisY = getY, axisWidth = getWidth, axisHeight = getHeight;
+    FlexBoxGetFunc crossX = getY, crossY = getX, crossWidth = getHeight, crossHeight = getWidth;
+    f32 mainAxisSize = totalWidth;
+    if (flags & UI_FLEX_DIR_COLUMN) {
+        axisX = getY;
+        axisY = getX;
+        axisWidth = getHeight;
+        axisHeight = getWidth;
+        crossX = getX;
+        crossY = getY;
+        crossWidth = getWidth;
+        crossHeight = getHeight;
+        mainAxisSize = totalHeight;
+    }
+
+
+    f32 spacingWidth = 0.0f;
+    f32 spacingHeight = 0.0f;
+
+    f32 mainAxisTotalSpacing = getWidth(desc->window) - mainAxisSize;
+    f32 mainAxisPadding = desc->padding * (numElements - 1);
+
+    f32 mainAxisSpacing = mainAxisTotalSpacing - mainAxisPadding;
+    if (mainAxisSpacing < 0) mainAxisSpacing = 0;
+
+    // Default: JUSTIFY_START
+    f32 mainAxisOffset = 0;
+    if (flags & UI_FLEX_JUSTIFY_CENTER) {
+        mainAxisOffset = mainAxisSpacing * 0.5f;
+    } else if (flags & UI_FLEX_JUSTIFY_END) {
+        mainAxisOffset = mainAxisSpacing;
+    }
+
+    bool rowDir = flags & UI_FLEX_DIR_ROW;
+
+    f32 offsetX = desc->window.x;
+    f32 offsetY = desc->window.y;
+    if (rowDir) offsetX += mainAxisOffset;
+    else offsetY += mainAxisOffset;
+
+    va_start(ap, numElements);
+    for (i32 i = 0; i < numElements; i++) {
+        f32 x = offsetX;
+        f32 y = offsetY;
+
+        Rectangle *rec = va_arg(ap, Rectangle *);
+        f32 crossOffset = 0;
+        if (flags & UI_FLEX_ALIGN_CENTER) {
+            crossOffset = (getHeight(desc->window) - getHeight(*rec)) * 0.5f;
+        } else if (flags & UI_FLEX_ALIGN_END) {
+            crossOffset = (getHeight(desc->window) - getHeight(*rec));
+        }
+        if (rowDir) {
+            offsetX += rec->width + spacingWidth + desc->padding;
+            y += crossOffset;
+        } else {
+            offsetY += rec->height + spacingHeight + desc->padding;
+            x += crossOffset;
+        }
+
+
+        rec->x = x;
+        rec->y = y;
+
+    }
+    va_end(ap);
+}